shallow.c: implement a generic shallow boundary finder based on rev-list
[git] / upload-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "sideband.h"
5 #include "tag.h"
6 #include "object.h"
7 #include "commit.h"
8 #include "exec_cmd.h"
9 #include "diff.h"
10 #include "revision.h"
11 #include "list-objects.h"
12 #include "run-command.h"
13 #include "connect.h"
14 #include "sigchain.h"
15 #include "version.h"
16 #include "string-list.h"
17
18 static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<n>] <dir>";
19
20 /* Remember to update object flag allocation in object.h */
21 #define THEY_HAVE       (1u << 11)
22 #define OUR_REF         (1u << 12)
23 #define WANTED          (1u << 13)
24 #define COMMON_KNOWN    (1u << 14)
25 #define REACHABLE       (1u << 15)
26
27 #define SHALLOW         (1u << 16)
28 #define NOT_SHALLOW     (1u << 17)
29 #define CLIENT_SHALLOW  (1u << 18)
30 #define HIDDEN_REF      (1u << 19)
31
32 static unsigned long oldest_have;
33
34 static int multi_ack;
35 static int no_done;
36 static int use_thin_pack, use_ofs_delta, use_include_tag;
37 static int no_progress, daemon_mode;
38 /* Allow specifying sha1 if it is a ref tip. */
39 #define ALLOW_TIP_SHA1  01
40 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
41 #define ALLOW_REACHABLE_SHA1    02
42 static unsigned int allow_unadvertised_object_request;
43 static int shallow_nr;
44 static struct object_array have_obj;
45 static struct object_array want_obj;
46 static struct object_array extra_edge_obj;
47 static unsigned int timeout;
48 static int keepalive = 5;
49 /* 0 for no sideband,
50  * otherwise maximum packet size (up to 65520 bytes).
51  */
52 static int use_sideband;
53 static int advertise_refs;
54 static int stateless_rpc;
55
56 static void reset_timeout(void)
57 {
58         alarm(timeout);
59 }
60
61 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
62 {
63         if (use_sideband)
64                 return send_sideband(1, fd, data, sz, use_sideband);
65         if (fd == 3)
66                 /* emergency quit */
67                 fd = 2;
68         if (fd == 2) {
69                 /* XXX: are we happy to lose stuff here? */
70                 xwrite(fd, data, sz);
71                 return sz;
72         }
73         write_or_die(fd, data, sz);
74         return sz;
75 }
76
77 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
78 {
79         FILE *fp = cb_data;
80         if (graft->nr_parent == -1)
81                 fprintf(fp, "--shallow %s\n", oid_to_hex(&graft->oid));
82         return 0;
83 }
84
85 static void create_pack_file(void)
86 {
87         struct child_process pack_objects = CHILD_PROCESS_INIT;
88         char data[8193], progress[128];
89         char abort_msg[] = "aborting due to possible repository "
90                 "corruption on the remote side.";
91         int buffered = -1;
92         ssize_t sz;
93         const char *argv[13];
94         int i, arg = 0;
95         FILE *pipe_fd;
96
97         if (shallow_nr) {
98                 argv[arg++] = "--shallow-file";
99                 argv[arg++] = "";
100         }
101         argv[arg++] = "pack-objects";
102         argv[arg++] = "--revs";
103         if (use_thin_pack)
104                 argv[arg++] = "--thin";
105
106         argv[arg++] = "--stdout";
107         if (shallow_nr)
108                 argv[arg++] = "--shallow";
109         if (!no_progress)
110                 argv[arg++] = "--progress";
111         if (use_ofs_delta)
112                 argv[arg++] = "--delta-base-offset";
113         if (use_include_tag)
114                 argv[arg++] = "--include-tag";
115         argv[arg++] = NULL;
116
117         pack_objects.in = -1;
118         pack_objects.out = -1;
119         pack_objects.err = -1;
120         pack_objects.git_cmd = 1;
121         pack_objects.argv = argv;
122
123         if (start_command(&pack_objects))
124                 die("git upload-pack: unable to fork git-pack-objects");
125
126         pipe_fd = xfdopen(pack_objects.in, "w");
127
128         if (shallow_nr)
129                 for_each_commit_graft(write_one_shallow, pipe_fd);
130
131         for (i = 0; i < want_obj.nr; i++)
132                 fprintf(pipe_fd, "%s\n",
133                         oid_to_hex(&want_obj.objects[i].item->oid));
134         fprintf(pipe_fd, "--not\n");
135         for (i = 0; i < have_obj.nr; i++)
136                 fprintf(pipe_fd, "%s\n",
137                         oid_to_hex(&have_obj.objects[i].item->oid));
138         for (i = 0; i < extra_edge_obj.nr; i++)
139                 fprintf(pipe_fd, "%s\n",
140                         oid_to_hex(&extra_edge_obj.objects[i].item->oid));
141         fprintf(pipe_fd, "\n");
142         fflush(pipe_fd);
143         fclose(pipe_fd);
144
145         /* We read from pack_objects.err to capture stderr output for
146          * progress bar, and pack_objects.out to capture the pack data.
147          */
148
149         while (1) {
150                 struct pollfd pfd[2];
151                 int pe, pu, pollsize;
152                 int ret;
153
154                 reset_timeout();
155
156                 pollsize = 0;
157                 pe = pu = -1;
158
159                 if (0 <= pack_objects.out) {
160                         pfd[pollsize].fd = pack_objects.out;
161                         pfd[pollsize].events = POLLIN;
162                         pu = pollsize;
163                         pollsize++;
164                 }
165                 if (0 <= pack_objects.err) {
166                         pfd[pollsize].fd = pack_objects.err;
167                         pfd[pollsize].events = POLLIN;
168                         pe = pollsize;
169                         pollsize++;
170                 }
171
172                 if (!pollsize)
173                         break;
174
175                 ret = poll(pfd, pollsize,
176                         keepalive < 0 ? -1 : 1000 * keepalive);
177
178                 if (ret < 0) {
179                         if (errno != EINTR) {
180                                 error("poll failed, resuming: %s",
181                                       strerror(errno));
182                                 sleep(1);
183                         }
184                         continue;
185                 }
186                 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
187                         /* Status ready; we ship that in the side-band
188                          * or dump to the standard error.
189                          */
190                         sz = xread(pack_objects.err, progress,
191                                   sizeof(progress));
192                         if (0 < sz)
193                                 send_client_data(2, progress, sz);
194                         else if (sz == 0) {
195                                 close(pack_objects.err);
196                                 pack_objects.err = -1;
197                         }
198                         else
199                                 goto fail;
200                         /* give priority to status messages */
201                         continue;
202                 }
203                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
204                         /* Data ready; we keep the last byte to ourselves
205                          * in case we detect broken rev-list, so that we
206                          * can leave the stream corrupted.  This is
207                          * unfortunate -- unpack-objects would happily
208                          * accept a valid packdata with trailing garbage,
209                          * so appending garbage after we pass all the
210                          * pack data is not good enough to signal
211                          * breakage to downstream.
212                          */
213                         char *cp = data;
214                         ssize_t outsz = 0;
215                         if (0 <= buffered) {
216                                 *cp++ = buffered;
217                                 outsz++;
218                         }
219                         sz = xread(pack_objects.out, cp,
220                                   sizeof(data) - outsz);
221                         if (0 < sz)
222                                 ;
223                         else if (sz == 0) {
224                                 close(pack_objects.out);
225                                 pack_objects.out = -1;
226                         }
227                         else
228                                 goto fail;
229                         sz += outsz;
230                         if (1 < sz) {
231                                 buffered = data[sz-1] & 0xFF;
232                                 sz--;
233                         }
234                         else
235                                 buffered = -1;
236                         sz = send_client_data(1, data, sz);
237                         if (sz < 0)
238                                 goto fail;
239                 }
240
241                 /*
242                  * We hit the keepalive timeout without saying anything; send
243                  * an empty message on the data sideband just to let the other
244                  * side know we're still working on it, but don't have any data
245                  * yet.
246                  *
247                  * If we don't have a sideband channel, there's no room in the
248                  * protocol to say anything, so those clients are just out of
249                  * luck.
250                  */
251                 if (!ret && use_sideband) {
252                         static const char buf[] = "0005\1";
253                         write_or_die(1, buf, 5);
254                 }
255         }
256
257         if (finish_command(&pack_objects)) {
258                 error("git upload-pack: git-pack-objects died with error.");
259                 goto fail;
260         }
261
262         /* flush the data */
263         if (0 <= buffered) {
264                 data[0] = buffered;
265                 sz = send_client_data(1, data, 1);
266                 if (sz < 0)
267                         goto fail;
268                 fprintf(stderr, "flushed.\n");
269         }
270         if (use_sideband)
271                 packet_flush(1);
272         return;
273
274  fail:
275         send_client_data(3, abort_msg, sizeof(abort_msg));
276         die("git upload-pack: %s", abort_msg);
277 }
278
279 static int got_sha1(const char *hex, unsigned char *sha1)
280 {
281         struct object *o;
282         int we_knew_they_have = 0;
283
284         if (get_sha1_hex(hex, sha1))
285                 die("git upload-pack: expected SHA1 object, got '%s'", hex);
286         if (!has_sha1_file(sha1))
287                 return -1;
288
289         o = parse_object(sha1);
290         if (!o)
291                 die("oops (%s)", sha1_to_hex(sha1));
292         if (o->type == OBJ_COMMIT) {
293                 struct commit_list *parents;
294                 struct commit *commit = (struct commit *)o;
295                 if (o->flags & THEY_HAVE)
296                         we_knew_they_have = 1;
297                 else
298                         o->flags |= THEY_HAVE;
299                 if (!oldest_have || (commit->date < oldest_have))
300                         oldest_have = commit->date;
301                 for (parents = commit->parents;
302                      parents;
303                      parents = parents->next)
304                         parents->item->object.flags |= THEY_HAVE;
305         }
306         if (!we_knew_they_have) {
307                 add_object_array(o, NULL, &have_obj);
308                 return 1;
309         }
310         return 0;
311 }
312
313 static int reachable(struct commit *want)
314 {
315         struct commit_list *work = NULL;
316
317         commit_list_insert_by_date(want, &work);
318         while (work) {
319                 struct commit_list *list;
320                 struct commit *commit = pop_commit(&work);
321
322                 if (commit->object.flags & THEY_HAVE) {
323                         want->object.flags |= COMMON_KNOWN;
324                         break;
325                 }
326                 if (!commit->object.parsed)
327                         parse_object(commit->object.oid.hash);
328                 if (commit->object.flags & REACHABLE)
329                         continue;
330                 commit->object.flags |= REACHABLE;
331                 if (commit->date < oldest_have)
332                         continue;
333                 for (list = commit->parents; list; list = list->next) {
334                         struct commit *parent = list->item;
335                         if (!(parent->object.flags & REACHABLE))
336                                 commit_list_insert_by_date(parent, &work);
337                 }
338         }
339         want->object.flags |= REACHABLE;
340         clear_commit_marks(want, REACHABLE);
341         free_commit_list(work);
342         return (want->object.flags & COMMON_KNOWN);
343 }
344
345 static int ok_to_give_up(void)
346 {
347         int i;
348
349         if (!have_obj.nr)
350                 return 0;
351
352         for (i = 0; i < want_obj.nr; i++) {
353                 struct object *want = want_obj.objects[i].item;
354
355                 if (want->flags & COMMON_KNOWN)
356                         continue;
357                 want = deref_tag(want, "a want line", 0);
358                 if (!want || want->type != OBJ_COMMIT) {
359                         /* no way to tell if this is reachable by
360                          * looking at the ancestry chain alone, so
361                          * leave a note to ourselves not to worry about
362                          * this object anymore.
363                          */
364                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
365                         continue;
366                 }
367                 if (!reachable((struct commit *)want))
368                         return 0;
369         }
370         return 1;
371 }
372
373 static int get_common_commits(void)
374 {
375         unsigned char sha1[20];
376         char last_hex[41];
377         int got_common = 0;
378         int got_other = 0;
379         int sent_ready = 0;
380
381         save_commit_buffer = 0;
382
383         for (;;) {
384                 char *line = packet_read_line(0, NULL);
385                 const char *arg;
386
387                 reset_timeout();
388
389                 if (!line) {
390                         if (multi_ack == 2 && got_common
391                             && !got_other && ok_to_give_up()) {
392                                 sent_ready = 1;
393                                 packet_write(1, "ACK %s ready\n", last_hex);
394                         }
395                         if (have_obj.nr == 0 || multi_ack)
396                                 packet_write(1, "NAK\n");
397
398                         if (no_done && sent_ready) {
399                                 packet_write(1, "ACK %s\n", last_hex);
400                                 return 0;
401                         }
402                         if (stateless_rpc)
403                                 exit(0);
404                         got_common = 0;
405                         got_other = 0;
406                         continue;
407                 }
408                 if (skip_prefix(line, "have ", &arg)) {
409                         switch (got_sha1(arg, sha1)) {
410                         case -1: /* they have what we do not */
411                                 got_other = 1;
412                                 if (multi_ack && ok_to_give_up()) {
413                                         const char *hex = sha1_to_hex(sha1);
414                                         if (multi_ack == 2) {
415                                                 sent_ready = 1;
416                                                 packet_write(1, "ACK %s ready\n", hex);
417                                         } else
418                                                 packet_write(1, "ACK %s continue\n", hex);
419                                 }
420                                 break;
421                         default:
422                                 got_common = 1;
423                                 memcpy(last_hex, sha1_to_hex(sha1), 41);
424                                 if (multi_ack == 2)
425                                         packet_write(1, "ACK %s common\n", last_hex);
426                                 else if (multi_ack)
427                                         packet_write(1, "ACK %s continue\n", last_hex);
428                                 else if (have_obj.nr == 1)
429                                         packet_write(1, "ACK %s\n", last_hex);
430                                 break;
431                         }
432                         continue;
433                 }
434                 if (!strcmp(line, "done")) {
435                         if (have_obj.nr > 0) {
436                                 if (multi_ack)
437                                         packet_write(1, "ACK %s\n", last_hex);
438                                 return 0;
439                         }
440                         packet_write(1, "NAK\n");
441                         return -1;
442                 }
443                 die("git upload-pack: expected SHA1 list, got '%s'", line);
444         }
445 }
446
447 static int is_our_ref(struct object *o)
448 {
449         int allow_hidden_ref = (allow_unadvertised_object_request &
450                         (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
451         return o->flags & ((allow_hidden_ref ? HIDDEN_REF : 0) | OUR_REF);
452 }
453
454 static int has_unreachable(struct object_array *src)
455 {
456         static const char *argv[] = {
457                 "rev-list", "--stdin", NULL,
458         };
459         static struct child_process cmd = CHILD_PROCESS_INIT;
460         struct object *o;
461         char namebuf[42]; /* ^ + SHA-1 + LF */
462         int i;
463
464         cmd.argv = argv;
465         cmd.git_cmd = 1;
466         cmd.no_stderr = 1;
467         cmd.in = -1;
468         cmd.out = -1;
469
470         /*
471          * If the next rev-list --stdin encounters an unknown commit,
472          * it terminates, which will cause SIGPIPE in the write loop
473          * below.
474          */
475         sigchain_push(SIGPIPE, SIG_IGN);
476
477         if (start_command(&cmd))
478                 goto error;
479
480         namebuf[0] = '^';
481         namebuf[41] = '\n';
482         for (i = get_max_object_index(); 0 < i; ) {
483                 o = get_indexed_object(--i);
484                 if (!o)
485                         continue;
486                 if (!is_our_ref(o))
487                         continue;
488                 memcpy(namebuf + 1, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
489                 if (write_in_full(cmd.in, namebuf, 42) < 0)
490                         goto error;
491         }
492         namebuf[40] = '\n';
493         for (i = 0; i < src->nr; i++) {
494                 o = src->objects[i].item;
495                 if (is_our_ref(o))
496                         continue;
497                 memcpy(namebuf, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
498                 if (write_in_full(cmd.in, namebuf, 41) < 0)
499                         goto error;
500         }
501         close(cmd.in);
502         cmd.in = -1;
503
504         /*
505          * The commits out of the rev-list are not ancestors of
506          * our ref.
507          */
508         i = read_in_full(cmd.out, namebuf, 1);
509         if (i)
510                 goto error;
511         close(cmd.out);
512         cmd.out = -1;
513
514         /*
515          * rev-list may have died by encountering a bad commit
516          * in the history, in which case we do want to bail out
517          * even when it showed no commit.
518          */
519         if (finish_command(&cmd))
520                 goto error;
521
522         sigchain_pop(SIGPIPE);
523
524         /* All the non-tip ones are ancestors of what we advertised */
525         return 0;
526
527 error:
528         sigchain_pop(SIGPIPE);
529
530         if (cmd.in >= 0)
531                 close(cmd.in);
532         if (cmd.out >= 0)
533                 close(cmd.out);
534         return 1;
535 }
536
537 static void check_non_tip(void)
538 {
539         int i;
540
541         /*
542          * In the normal in-process case without
543          * uploadpack.allowReachableSHA1InWant,
544          * non-tip requests can never happen.
545          */
546         if (!stateless_rpc && !(allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1))
547                 goto error;
548         if (!has_unreachable(&want_obj))
549                 /* All the non-tip ones are ancestors of what we advertised */
550                 return;
551
552 error:
553         /* Pick one of them (we know there at least is one) */
554         for (i = 0; i < want_obj.nr; i++) {
555                 struct object *o = want_obj.objects[i].item;
556                 if (!is_our_ref(o))
557                         die("git upload-pack: not our ref %s",
558                             oid_to_hex(&o->oid));
559         }
560 }
561
562 static void send_shallow(struct commit_list *result)
563 {
564         while (result) {
565                 struct object *object = &result->item->object;
566                 if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
567                         packet_write(1, "shallow %s",
568                                      oid_to_hex(&object->oid));
569                         register_shallow(object->oid.hash);
570                         shallow_nr++;
571                 }
572                 result = result->next;
573         }
574 }
575
576 static void send_unshallow(const struct object_array *shallows)
577 {
578         int i;
579
580         for (i = 0; i < shallows->nr; i++) {
581                 struct object *object = shallows->objects[i].item;
582                 if (object->flags & NOT_SHALLOW) {
583                         struct commit_list *parents;
584                         packet_write(1, "unshallow %s",
585                                      oid_to_hex(&object->oid));
586                         object->flags &= ~CLIENT_SHALLOW;
587                         /*
588                          * We want to _register_ "object" as shallow, but we
589                          * also need to traverse object's parents to deepen a
590                          * shallow clone. Unregister it for now so we can
591                          * parse and add the parents to the want list, then
592                          * re-register it.
593                          */
594                         unregister_shallow(object->oid.hash);
595                         object->parsed = 0;
596                         parse_commit_or_die((struct commit *)object);
597                         parents = ((struct commit *)object)->parents;
598                         while (parents) {
599                                 add_object_array(&parents->item->object,
600                                                  NULL, &want_obj);
601                                 parents = parents->next;
602                         }
603                         add_object_array(object, NULL, &extra_edge_obj);
604                 }
605                 /* make sure commit traversal conforms to client */
606                 register_shallow(object->oid.hash);
607         }
608 }
609
610 static void deepen(int depth, const struct object_array *shallows)
611 {
612         if (depth == INFINITE_DEPTH && !is_repository_shallow()) {
613                 int i;
614
615                 for (i = 0; i < shallows->nr; i++) {
616                         struct object *object = shallows->objects[i].item;
617                         object->flags |= NOT_SHALLOW;
618                 }
619         } else {
620                 struct commit_list *result;
621
622                 result = get_shallow_commits(&want_obj, depth,
623                                              SHALLOW, NOT_SHALLOW);
624                 send_shallow(result);
625                 free_commit_list(result);
626         }
627
628         send_unshallow(shallows);
629         packet_flush(1);
630 }
631
632 static void receive_needs(void)
633 {
634         struct object_array shallows = OBJECT_ARRAY_INIT;
635         int depth = 0;
636         int has_non_tip = 0;
637
638         shallow_nr = 0;
639         for (;;) {
640                 struct object *o;
641                 const char *features;
642                 unsigned char sha1_buf[20];
643                 char *line = packet_read_line(0, NULL);
644                 const char *arg;
645
646                 reset_timeout();
647                 if (!line)
648                         break;
649
650                 if (skip_prefix(line, "shallow ", &arg)) {
651                         unsigned char sha1[20];
652                         struct object *object;
653                         if (get_sha1_hex(arg, sha1))
654                                 die("invalid shallow line: %s", line);
655                         object = parse_object(sha1);
656                         if (!object)
657                                 continue;
658                         if (object->type != OBJ_COMMIT)
659                                 die("invalid shallow object %s", sha1_to_hex(sha1));
660                         if (!(object->flags & CLIENT_SHALLOW)) {
661                                 object->flags |= CLIENT_SHALLOW;
662                                 add_object_array(object, NULL, &shallows);
663                         }
664                         continue;
665                 }
666                 if (skip_prefix(line, "deepen ", &arg)) {
667                         char *end = NULL;
668                         depth = strtol(arg, &end, 0);
669                         if (!end || *end || depth <= 0)
670                                 die("Invalid deepen: %s", line);
671                         continue;
672                 }
673                 if (!skip_prefix(line, "want ", &arg) ||
674                     get_sha1_hex(arg, sha1_buf))
675                         die("git upload-pack: protocol error, "
676                             "expected to get sha, not '%s'", line);
677
678                 features = arg + 40;
679
680                 if (parse_feature_request(features, "multi_ack_detailed"))
681                         multi_ack = 2;
682                 else if (parse_feature_request(features, "multi_ack"))
683                         multi_ack = 1;
684                 if (parse_feature_request(features, "no-done"))
685                         no_done = 1;
686                 if (parse_feature_request(features, "thin-pack"))
687                         use_thin_pack = 1;
688                 if (parse_feature_request(features, "ofs-delta"))
689                         use_ofs_delta = 1;
690                 if (parse_feature_request(features, "side-band-64k"))
691                         use_sideband = LARGE_PACKET_MAX;
692                 else if (parse_feature_request(features, "side-band"))
693                         use_sideband = DEFAULT_PACKET_MAX;
694                 if (parse_feature_request(features, "no-progress"))
695                         no_progress = 1;
696                 if (parse_feature_request(features, "include-tag"))
697                         use_include_tag = 1;
698
699                 o = parse_object(sha1_buf);
700                 if (!o)
701                         die("git upload-pack: not our ref %s",
702                             sha1_to_hex(sha1_buf));
703                 if (!(o->flags & WANTED)) {
704                         o->flags |= WANTED;
705                         if (!is_our_ref(o))
706                                 has_non_tip = 1;
707                         add_object_array(o, NULL, &want_obj);
708                 }
709         }
710
711         /*
712          * We have sent all our refs already, and the other end
713          * should have chosen out of them. When we are operating
714          * in the stateless RPC mode, however, their choice may
715          * have been based on the set of older refs advertised
716          * by another process that handled the initial request.
717          */
718         if (has_non_tip)
719                 check_non_tip();
720
721         if (!use_sideband && daemon_mode)
722                 no_progress = 1;
723
724         if (depth == 0 && shallows.nr == 0)
725                 return;
726         if (depth > 0)
727                 deepen(depth, &shallows);
728         else
729                 if (shallows.nr > 0) {
730                         int i;
731                         for (i = 0; i < shallows.nr; i++)
732                                 register_shallow(shallows.objects[i].item->oid.hash);
733                 }
734
735         shallow_nr += shallows.nr;
736         free(shallows.objects);
737 }
738
739 /* return non-zero if the ref is hidden, otherwise 0 */
740 static int mark_our_ref(const char *refname, const char *refname_full,
741                         const struct object_id *oid)
742 {
743         struct object *o = lookup_unknown_object(oid->hash);
744
745         if (ref_is_hidden(refname, refname_full)) {
746                 o->flags |= HIDDEN_REF;
747                 return 1;
748         }
749         o->flags |= OUR_REF;
750         return 0;
751 }
752
753 static int check_ref(const char *refname_full, const struct object_id *oid,
754                      int flag, void *cb_data)
755 {
756         const char *refname = strip_namespace(refname_full);
757
758         mark_our_ref(refname, refname_full, oid);
759         return 0;
760 }
761
762 static void format_symref_info(struct strbuf *buf, struct string_list *symref)
763 {
764         struct string_list_item *item;
765
766         if (!symref->nr)
767                 return;
768         for_each_string_list_item(item, symref)
769                 strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
770 }
771
772 static int send_ref(const char *refname, const struct object_id *oid,
773                     int flag, void *cb_data)
774 {
775         static const char *capabilities = "multi_ack thin-pack side-band"
776                 " side-band-64k ofs-delta shallow no-progress"
777                 " include-tag multi_ack_detailed";
778         const char *refname_nons = strip_namespace(refname);
779         struct object_id peeled;
780
781         if (mark_our_ref(refname_nons, refname, oid))
782                 return 0;
783
784         if (capabilities) {
785                 struct strbuf symref_info = STRBUF_INIT;
786
787                 format_symref_info(&symref_info, cb_data);
788                 packet_write(1, "%s %s%c%s%s%s%s%s agent=%s\n",
789                              oid_to_hex(oid), refname_nons,
790                              0, capabilities,
791                              (allow_unadvertised_object_request & ALLOW_TIP_SHA1) ?
792                                      " allow-tip-sha1-in-want" : "",
793                              (allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1) ?
794                                      " allow-reachable-sha1-in-want" : "",
795                              stateless_rpc ? " no-done" : "",
796                              symref_info.buf,
797                              git_user_agent_sanitized());
798                 strbuf_release(&symref_info);
799         } else {
800                 packet_write(1, "%s %s\n", oid_to_hex(oid), refname_nons);
801         }
802         capabilities = NULL;
803         if (!peel_ref(refname, peeled.hash))
804                 packet_write(1, "%s %s^{}\n", oid_to_hex(&peeled), refname_nons);
805         return 0;
806 }
807
808 static int find_symref(const char *refname, const struct object_id *oid,
809                        int flag, void *cb_data)
810 {
811         const char *symref_target;
812         struct string_list_item *item;
813         struct object_id unused;
814
815         if ((flag & REF_ISSYMREF) == 0)
816                 return 0;
817         symref_target = resolve_ref_unsafe(refname, 0, unused.hash, &flag);
818         if (!symref_target || (flag & REF_ISSYMREF) == 0)
819                 die("'%s' is a symref but it is not?", refname);
820         item = string_list_append(cb_data, refname);
821         item->util = xstrdup(symref_target);
822         return 0;
823 }
824
825 static void upload_pack(void)
826 {
827         struct string_list symref = STRING_LIST_INIT_DUP;
828
829         head_ref_namespaced(find_symref, &symref);
830
831         if (advertise_refs || !stateless_rpc) {
832                 reset_timeout();
833                 head_ref_namespaced(send_ref, &symref);
834                 for_each_namespaced_ref(send_ref, &symref);
835                 advertise_shallow_grafts(1);
836                 packet_flush(1);
837         } else {
838                 head_ref_namespaced(check_ref, NULL);
839                 for_each_namespaced_ref(check_ref, NULL);
840         }
841         string_list_clear(&symref, 1);
842         if (advertise_refs)
843                 return;
844
845         receive_needs();
846         if (want_obj.nr) {
847                 get_common_commits();
848                 create_pack_file();
849         }
850 }
851
852 static int upload_pack_config(const char *var, const char *value, void *unused)
853 {
854         if (!strcmp("uploadpack.allowtipsha1inwant", var)) {
855                 if (git_config_bool(var, value))
856                         allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
857                 else
858                         allow_unadvertised_object_request &= ~ALLOW_TIP_SHA1;
859         } else if (!strcmp("uploadpack.allowreachablesha1inwant", var)) {
860                 if (git_config_bool(var, value))
861                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
862                 else
863                         allow_unadvertised_object_request &= ~ALLOW_REACHABLE_SHA1;
864         } else if (!strcmp("uploadpack.keepalive", var)) {
865                 keepalive = git_config_int(var, value);
866                 if (!keepalive)
867                         keepalive = -1;
868         }
869         return parse_hide_refs_config(var, value, "uploadpack");
870 }
871
872 int main(int argc, char **argv)
873 {
874         char *dir;
875         int i;
876         int strict = 0;
877
878         git_setup_gettext();
879
880         packet_trace_identity("upload-pack");
881         git_extract_argv0_path(argv[0]);
882         check_replace_refs = 0;
883
884         for (i = 1; i < argc; i++) {
885                 const char *arg = argv[i];
886
887                 if (arg[0] != '-')
888                         break;
889                 if (!strcmp(arg, "--advertise-refs")) {
890                         advertise_refs = 1;
891                         continue;
892                 }
893                 if (!strcmp(arg, "--stateless-rpc")) {
894                         stateless_rpc = 1;
895                         continue;
896                 }
897                 if (!strcmp(arg, "--strict")) {
898                         strict = 1;
899                         continue;
900                 }
901                 if (skip_prefix(arg, "--timeout=", &arg)) {
902                         timeout = atoi(arg);
903                         daemon_mode = 1;
904                         continue;
905                 }
906                 if (!strcmp(arg, "--")) {
907                         i++;
908                         break;
909                 }
910         }
911
912         if (i != argc-1)
913                 usage(upload_pack_usage);
914
915         setup_path();
916
917         dir = argv[i];
918
919         if (!enter_repo(dir, strict))
920                 die("'%s' does not appear to be a git repository", dir);
921
922         git_config(upload_pack_config, NULL);
923         upload_pack();
924         return 0;
925 }